Gradually more and more organizations are opting for outsourcing data to remote cloud service providers (CSPs). clients can rent the CSPs storage infrastructure to store and get back almost infinite amount of data by paying amount per month. On behalf of an improved level of scalability, availability, and durability, some clients may want their data to be virtual on multiple servers across multiple data centers. The more copies the CSP is asked to store, the more amount the clients are charged. As a result, clients need to have a strong assurance that the CSP is storing all data copies that are decided upon in the service contract, and all these copies are reliable with the most recent modifications issued by the clients. Map-based provable multicopy dynamic data possession (MB-PMDDP) method is being proposed in this paper and consists of the following features: 1) it affords an proof to the clients that the CSP is not corrupt by storing less copies; 2) it supports outsourcing of dynamic data, i.e., it supports block-level functions, such as block alteration, addition, deletion, and append; and 3) it permits official users to effortlessly access the file copies stored by the CSP. In addition, we discuss the security against colluding servers, and discuss how to recognize corrupted copies by a little revising the projected scheme.

Bindu et al., International Journal of Computer Engineering In Research Trends Volume 3, Issue 1, January-2016, pp. 6-12